THE ART AND SCIENCE OF CONCERT HALL ACOUSTICS

IV. PROCEDURE

Thirty-one simulations cases were run. Each belonged to one of the following five categories:

(1) Simple Rectangular Hall

(2) Sunset Center, Carmel California (Shoebox Hall with Proscenium)

(3) Gallagher Bluedorn Grand Hall, Univ. of N. Iowa (Horseshoe with deep stage)

(4) Ted Mann Hall, Univ. of MN (Shoebox with Reverse Fan)

(5) Bubble Hall (Hypothetical Hemi-spherical or Hemi-Ellipsoidal)

The Simple Rectangular Hall was a demonstration example that came with the ODEON package. Geometry and materials for the construction for the Sunset Center was estimated from pictures of the hall and discussions with people who have been there; information for the renovated hall came from a promotional brochure for that renovation. Geometry and materials for Gallagher-Bluedorn and Ted Mann Halls were made from estimates while visiting each of these two halls for two days. The models for these halls were constructed while sitting in each hall. The geometry and materials for the Bubble Hall were designed from scratch at SSESCO.

All halls were simulated with ODEON 4.2 on a 750 MHz PC with 786 Mbytes of memory and 25 Gbytes of disk.. Construction of the computer model for each of the three concert halls (Sunset, Gallagher-Bluedorn, and Ted Mann) took 2 to 3 days. Computer simulations took anywhere from a few minutes to a few days depending on the number of rays traced and the resolution of the grid on which many of the statistics are collected. Typically 1000 to 4000 rays per sound source were sufficient according to guidelines in the user’s manual.